Metroid for sure
again metroid surpasses startrek in timeline
just comparing the GFS Olympus as A flagship (means theres more of them) and it's bigger then anything the federation owns (just using my bigger = better theory here)
Samus Aran's Power Suit vs (unarmored soldiers??)
Metroid Fightercraft VS Shuttle pod's... (lol?)
metroid badguys vs startrek badguys (the borg r nothing compared 2 space pirates... , and species 8472 in turn = nothing compared 2 phazon...
Metroid = a more dangerous universe, compared 2 StarTrek
so my choice definatly falls on Metroid